WO2012066355A1

WO2012066355A1 - Improvements in or relating to inkjet printers

Info

Publication number: WO2012066355A1
Application number: PCT/GB2011/052274
Authority: WO
Inventors: Jonathan Morgan; Steven Mark Hatch
Original assignee: Domino Printing Sciences PLC
Current assignee: Domino Printing Sciences PLC
Priority date: 2010-11-19
Filing date: 2011-11-21
Publication date: 2012-05-24
Anticipated expiration: 2013-05-19
Also published as: GB2499156B; GB201309189D0; GB2499156A; GB201019684D0

Abstract

The invention provides an ink service module having both an ink reservoir and a filter enclosure. The filter enclosure may be located within the ink reservoir but sealed there-from to allow the filter to operate at system pressure whilst the ink reservoir is at ambient pressure.

Description

IMPROVEMENTS IN OR RELATING TO INKJET PRINTERS

Field of the Invention

This invention relates to inkjet printers and, more particularly, to an ink filtration arrangement in a continuous inkjet (CIJ) printer.

Background to the Invention

Ink or solvent make-up is typically supplied to inkjet printing systems through the use of disposable ink bottles. An ink bottle may be mounted on an ink reservoir that includes a mating feature that allows ink to pass from the ink bottle into the ink reservoir. Each ink bottle retains a finite amount of ink, typically a pint or litre of ink.

The properties of the printing ink may deteriorate over time. How long this may take depends upon a number of factors such as the rate at which new ink and/or make-up is added, the environment and the ingredients from which the ink is made.

All manufacturers of continuous inkjet printing systems provide filtration within the ink system to limit the size of, and trap, particulate matter that may form in the ink. Such filters require replacement at regular service intervals. At this time it is also common practice to replace the bulk of the ink in the printer with fresh ink. Historically this service action is undertaken by skilled personnel, e.g service technician or maintenance staff and requires the printer to be taken out of service and off line for 30 to 60 minutes.

In the case of the Domino A-series printers currently manufactured by the applicant, the main ink filter is separate from the ink reservoir and is connected into the ink system by flexible tubing. This arrangement presents a cluttered appearance and the end connections on the tubes are a potential source of leakage.

There is now a move to include the filters in a core or module which includes other service items and fresh ink so that, when it is time to service the printer, all the service items are replaced in a single step. International Patent Application WO 2009/049150 shows such a system however the service module described also includes components such as the system pump and a jet pump assembly. To replace these components at the service intervals dictated by filter life and ink quality adds considerable expense.

It is an object of this invention to provide a continuous inkjet printer, and/or one or more components therefore, which will go at least some way in addressing aforementioned problems; or which will at least provide a novel and useful choice.

Summary of the Invention

Accordingly, the invention provides an ink service module for a continuous inkjet printer, said module having an ink reservoir and a filter, said module being characterised in that said filter is positioned in an enclosure within said module said enclosure being sealed from said ink reservoir and having connections to an exterior of said module.

Preferably said enclosure is located within said ink reservoir.

Preferably said ink reservoir and said enclosure are sealed within said module Preferably said module further includes an array of connectors on a common exterior wall thereof, some of said connectors being in communication with said enclosure and some of said connectors being in communication with said ink reservoir.

In a second aspect the invention provides a continuous inkjet printer including an ink circulation system and an ink service module, said ink service module having an ink reservoir, a filter, and a plurality of connections to enable connection of said module to said ink circulation system, said printer being characterised in that said filter is positioned in an enclosure within said module, a first set of said connections communicating said enclosure with said ink circulating system and a second set of said connections communicating said ink reservoir with said ink circulating system.

Preferably said connections are arranged on a common side of said module.

Many variations in the way the present invention can be performed will present themselves to those skilled in the art. The description which follows is intended as an illustration only of one means of performing the invention and the lack of description of variants or equivalents should not be regarded as limiting. Wherever possible, a description of a specific element should be deemed to include any and all equivalents thereof whether in existence now or in the future.

Brief Description of the Drawings

The various aspects of the invention, in one preferred form, will now be described with reference to the accompanying drawings in which: Figure 1: shows an isometric view, from the rear, of an ink service module according to the invention;

Figure 2: shows a sectional view of the module shown in Figure 1 ; and

Figure 3: shows the module assembled on to an ink circulation system/

Detailed Description of Working Embodiment

The invention provides an ink service module 5 for attachment to the ink circulation system 6 of a continuous inkjet printer. To this end a line of spigot connectors 7 are provided along one side of the module 5, the connectors 7 engaging in corresponding sockets (not shown) in the ink circulation system. Located in the top of the module 5 is a further connection socket 8 whereby an ink cartridge (not shown) may be mounted on the module 5 to replace ink from the module which is consumed through printing.

A solvent make-up module 9 may be similarly mounted to the ink circulation system 6.

Referring particularly to Figure 2, the ink service module 5 has an ink reservoir 10 and a filter 11, the filter being located in an enclosure 12 which is within, but sealed from, the ink reservoir and communicates with the exterior of the module. Thus, the filter enclosure 12, in use, will be subject to full system pressure of about 5 bar while the ink reservoir is at ambient pressure.

It should be appreciated that the module 5 is a fully sealed item. At the specified service interval, the module including filter(s) and any ink therein, is removed from the ink circulation system 6 and discarded. When the module 5 is connected into the ink system 6, the filter enclosure 12 communicates with the ink circulation system via a first set of two spigots 7b and 7c. The remaining spigots convey ink, including ink to and from the ink reservoir 12, at lower pressures. Because of the unique manner of isolating and mounting the filter 11 within the service module, longer life components such as the circulating pump may be included externally and thus not be subject to replacement at the same time as the service module. This significantly reduces servicing costs.

It will thus be appreciated that the invention provides a replaceable ink module that satisfies the requirement to provide service items such as replacement ink and filters in a single unit, whilst providing for different working pressures to be realised in the module when in use, and not including expensive items such as pumps.

Claims

1. An ink service module for a continuous inkjet printer, said module having an ink reservoir and a filter, said module being characterised in that said filter is positioned in an enclosure within said module said enclosure being sealed from said ink reservoir and having connections to an exterior of said module.

2. A module as claimed in claim 1 wherein said enclosure is located within said ink reservoir.

3. A module as claimed in claim 1 or claim 2 wherein said ink reservoir and said enclosure are sealed within said module

4. A module as claimed in any one of the preceding claims further

including an array of connectors on a common exterior wall thereof, some of said connectors being in communication with said enclosure and some of said connectors being in communication with said ink reservoir.

5. A continuous inkjet printer including an ink circulation system and an ink service module, said ink service module having an ink reservoir, a filter, and a plurality of connections to enable connection of said module to said ink circulation system, said printer being characterised in that said filter is positioned in an enclosure within said module, a first set of said connections communicating said enclosure with said ink circulating system and a second set of said connections communicating said ink reservoir with said ink circulating system.

6. A printer as claimed in claim 4 wherein said connections are arranged on a common side of said module.